シンボルライブラリ¶

Groups and smart groups¶

You can organize symbols into different categories. These categories, listed in the panel at the left, can be static (called Group) or dynamic (named Smart Group). A group is smart when its symbols are dynamically fetched according to conditions set. See figure_smart_group:

To create a group, right click on an existing group or on the main Groups directory in the left of the dialog. You can also select a group and click the ^{Add Group} button. The new group will be a sub-group of the selected one.

Create Smart Group is similar to creating group, but instead select Smart Groups. The dialog box allows user to choose the expression to select symbols in order to appear in the smart group (contains some tags, member of a group, have a string in its name, etc.). Any symbol that satisfies the entered condition(s) is automatically added to the smart group.

スマートグループを作成する

To remove a group or a smart group, right click on the group and select Remove Group or select it and push ^{Remove Group} button.

Unlike the smart groups that automatically fetch their belonged symbols, simple groups are filled by the user. To add a symbol into a group, you can either right click on a symbol, choose Apply Group and then the group name. There is a second way to add several symbols into a group: just select the group, click and choose Group Symbols. All symbols display a checkbox that allows you to add the symbol into the selected groups. When selection is finished, you can click the same button, and choose Finish Grouping.

All the symbols that are not placed under a custom group belong to a default group named Ungrouped.

Add, Edit, Remove Symbol¶

Selecting a group returns in the right panel, if applicable, the list of symbols of the group (including its subgroups). These symbols are organized in four different tabs:

• Marker for point symbols
• Line for linear symbols
• Fill for surface symbols
• and カラーランプ.

To delete a symbol you no longer need, just select it and click ^{Remove item} (also available through right-click). The symbol will be deleted from the local symbols database.

The symbol list can be modified by adding new symbols with ^{Add item} button or modifying existing ones with ^{Edit item}. See シンボルセレクタ for further information.

Share symbols¶

The ^{Share item} tool, at the right bottom of the Style Library dialog, offers options to easily share symbols with others: users can indeed export their symbols and import symbols to their library.

Exporting symbols

You can export the selected symbols to PNG, SVG or XML file formats. Exporting to PNG or SVG (both not available for color ramp symbols) creates a file for each selected symbol, and the SVG folder can be added to SVG Paths in Settings ‣ Options to e.g. share these symbols on a network. The XML format generates a single file containing all the selected symbols. This file can then be imported in another user’s style library.

Importing symbols

You can extend your symbols library by importing new symbols. Just select Import from the drop-down list at the right bottom of the dialog. In the new dialog, you’ll need to :

• indicate the source of the symbols (it can be a .xml file on the disk or an url),
• give the name of the group under which the symbols will be put
• select the symbols you want to add to your library
• and press Import.

Note that import and export options are also available through right-click.

Importing symbols

カラーランプ¶

The Color ramp tab in the Style Manager presents different types of color ramps you can use to style layers.

カスタムカラーランプを作成するには、カラーランプ]タブをアクティブにし、 ^{項目を追加} ボタンをクリックします。ボタンは、ランプ・タイプを選択するドロップダウンリストを明らかにする：

• 勾配：開始色と終了色を指定して、 連続的 または 離散的 カラーランプを生成します。ランププレビューをダブルクリックすると、必要な数の中間色ストップを追加できます。

• Random: creates a random set of colors based on range of values for hue, saturation, value and opacity and a number of colors (classes)
• ColorBrewer: a set of predefined discrete color gradients you can custom the number of colors in the ramp
• or cpt-city: an access to a whole catalog of color gradients to locally save as gradient color.

You can use the Invert option while classifying the data with a color ramp. See figure_color_custom_ramp for an example of a custom color ramp and figure_color_cpt_city for the cpt-city Colors dialog.

複数のストップを持つカスタムグラデーションのカラーランプの例

The cpt-city option opens a new dialog with hundreds of themes included ‘out of the box’.

何百ものカラーランプを持つケープタウン市ダイアログ

シンボルレイヤーツリー¶

シンボルは、いくつかの シンボルレイヤー で構成できます。シンボルツリーは、後で結合されたこれらのシンボルレイヤーのオーバーレイを示し、新しいグローバルシンボルを形成します。また、シンボルのプロパティが変更されるとシンボル表現はすぐに動的に更新されます。

シンボルツリー項目を管理するためのツールセットが用意されており、選択したレベルに応じてダイアログの下部にさまざまなツールが有効になります。

• 新しいシンボルレイヤーを追加します。好きなだけシンボルを積み重ねることができます

• 選択されたシンボルレイヤーを除去

• シンボルレイヤーの色をロック： ロックされた色は、ユーザーがグローバル（または上部）シンボルレベルで色を変更したときに変化しないまま

• シンボルレイヤー(複数可) (のグループ)を複製する

• シンボルレイヤーを上または下に移動

シンボルを構成する¶

QGISでは、シンボルの構成は2つのステップで行われます：シンボルとシンボルレイヤー。

-- render the centroid of a feature
centroid( $geometry )

-- visually overlap features within a 100 map units distance from a point
-- feature, i.e generate a 100m buffer around the point
buffer( $geometry, 100 )

-- Given polygon layer1( id1, layer2_id, ...) and layer2( id2, fieldn...)
-- render layer1 with a line joining centroids of both where layer2_id = id2
make_line( centroid( $geometry ),
           centroid( geometry( get_feature( 'layer2', 'id2', attribute(
               $currentfeature, 'layer2_id') ) )
         )